The Node.js Agent no longer supports the proxy as of version 21.9.
Every Node.js Agent on a machine launches a proxy instance, creating a control directory for the proxy based on a unique combination of application, tier, and node names for the agent. The control directory contains the configuration for the agent and the domain control socket, which is what the agent uses to start an AppDynamics node.
If you are running multiple Node.js Agents on a single machine, you can configure them to use a shared Java proxy. Referred to as a "multi-tenant proxy," the shared proxy reduces the overhead of additional proxies and is a required configuration for external process managers, such as PM2.
You can use the Java proxy mode as the Node.js Agent supports the existing Java proxy.